Brake device



pnfil 18, 1939.

' 'i BRAKE DEvloE Filed May 24,' 1958 2 sheets-sheet 1 'Vlg I.

c. c. FARMER 'I 2,155,222

April 18, 1939. c. c. ll-ARMER .2,155,222

BRAKE DEVICE FiledMay 24, 1938 2 Sheets-Sheet 2 INVENTOR GLY DECTARMERATTORNEY Patented Apr. 1s, 1939 UNITI-:D vsnm-:s

. BRAKE navrcn Clyde C, Farmer, Pittsburgh, Pa., assig'fnorA to TheWestinghouse Air Brake Oompany, Wllmerding. Pa.. a corporation oi'Pennsylvania Application my 24, 193s, serial Na 209,649

n 17 This invention relates to brakes for railway vehicles and moreparticularly to brakes of the.

drum type having one or morebrake drums associated with one or morewheel and axle as- 5 semblies of the vehicle and which is adapted to befrictionally engaged by brake shoes disposed at one side thereof or atdiametrically opposite sides in clasp arrangement.

In high speed train service it has'been learned that the usual brakerigging having brake shoes which bear against the tread of the wheels ineffecting an application of the brakes is inadequate to produce the-desired braking action without undue wear andheating of the brake shoesand vehicle Wheels. This is ldue particularly to the fact'that the areaof that portion of the face of the brake shoe which frictionally'engages the .Iace of the tread of the wheel is limited in width to the-width of suchtreads and in length by the ability Aoi. the shoe towithstand warpage and breakage Vand by the proper'relationship of itseilective lengths to the diameter of the-wheel.

For the purpose of overcoming the above dif-v culties it has beenproposed to provide as many Awheel and axle assemblies of a vehicle as'is necessary with drum brakes in which' the brake shoes frictionallyengage one 'or more brake drums secured to each assembly.

The necessary limitations as to width of thetread of a wheel do notapply to a brake drum,

so that the drum may be made of a Width suiiicient to accommodate asmany brake 'shoes arranged side by side on one side or on diametricallyopposite sides oi the drum as is necessary to produce the desiredbraking action with a relatively low unit braking pressure on each shoe.In the 'drum brakes heretofore proposed the entire braking action iseiected through the medium of the brake drums, there being no shoes 4por other friction braking elements for engagement with the treads of thewheels.

It is Well known that where there is nothing to at least occasionallyfrictionally engage the treads of the wheels dirt is liable to collectthere- 45 on, which dirt tends to reduce adhesion between the wheel andrail and as a consequence impairs the eiilcacy of a brake application.Dlrt adher-l ing to the treads of the wheels also acts to cause thewheels' to pound on the -railand produce 50 objectionable noise and mayalso cause the wheel or rail or both to be damaged.

The principal object o f the invention is to provide a combined wheeland drum'brake mechanism for a railway vehicle which willbe free 55 ofthe above mentioned objectionable features.

Another objectoi the invention is to provide a brake mechanism having atleast one brake element arranged for frictional brakingengagement withthe thread of a. vehicle-wheel, at least one brake element arranged-forfrictional brakv ingv engagement with a brake drum secured to thewheel.. and mechanism for simultaneously` controlling the operation ofboth of the brake elements.

lAnother object of the invention is to provide 10' a combined wheel anddrum brake mechanism having friction brake elements adapted to beactuated to frictionally engage a wheel of the vehicle and a drum'rotatablefwith the wheel, and

also having a mechanism for actuating said ele- 15v ments andiorproportioning the power transmitted by the mechanism to each element topro'- vide the desired unit pressure on each element.

A further object of the invention is to provide a unit brake mechanismfor a wheel and axle 20 assembly of a railway vehicle, which mechanismcomprises two spaced brakedrums secured to the wheel and axle assembly,a brake element for engagement with the tread o1' each wheel, a brakeelement'for engagement with each drum, 25 and a system of operativelyconnected brake rigging' members foractuating saidelements.

A still further object of the invention is to provide a unit clasp brakemechanism i'or a wheel and axle assembly of a railway vehicle,`which 30Imechanism comprises a pair of spaced brake drums arranged one adjacenteach wheel of the assembly. brake elements disposed in clasp'arrangement about each wheel, brake elements disposed in clasparrangement about each brakev 35 drum, anda system of operativelyconnected brake rigging members and a single brake cylinder foractuating the brake elements.

Other objects and'advantages will appear in the following morefdetaileddescription of the 40 invention.

In the accompanying drawings Fig. l is a plan I view of a combined wheeland drum brake mechanismconstructed in accordance with the invention,the mechanism being shown applied toa wheel and axle assembly of arailway vehicle; and Fig. 2 is a sectional view takenv on the line 2-2of Fig. 1.

As shown in the drawings, the brake rigging is operatively associatedwith a wheel and axle assembly of a railway vehicle, which assembly maybe of the usual type comprising an axle I having secured' thereto in anydesired manner-wheels 2. The ends of the axle I may be journale'd in theusual journal boxes which may be disposed between the usual pedestaljaws of a truck frame of the vehicle ln some types vof trucks thejournal boxes and truck frame are rigidly connectedgtogether, while inother types the truck frame is spring supported from the wheel and axleassembly, and in these latter types of trucks the pedestal jaw membersare movable vertically withv the truck frame relative to the journalboxes. Since the trucks may be of any of. the

carried by brake heads 6. The brake shoes and brake heads at one side ofeach brake drum are spaced apart in a direction longitudinally of theaxle and are supported 'by hangers lwhich are pivotally connected to thebrake heads and to the Aframe of the truck in the usual manner, there ybeing a separate hanger for each brake head.

'Ihe brake heads 6 are provided with lateral slots 8. which are adaptedto accommodate the ends of laterally extending brake beams 9 and IIIwhich terminate short of the wheels'2 of the wheel and axle assembly.These brake beams rest on the brake heads and are therefore supportedfrom the truck frame by g the hangers 1. At a point located a shortdistance from the -outer longitudinal end vof each` brake beam, thebrake heads of each pair'of heads are operatively connected together bymeans of a laterally extending horizontally disposed equalizer leyer II,

the ends of the lever extending within the slots y 3 in the heads andbeing pivotally connected to each head by means of a pin I2. Theequalizer.

lever, intermediate itsends, is pivotally connected to the outer end ofshort spaced pull links I3 by means of a pin Iland the inner ends of thelinks are pivotally connected to the adjacent end of the adjacent brakebeam.

y It will be apparent from the foregoing descrip- Ation that the onlypositive connection `from the brake beams to A`the brakeheads arethrough the medium of the links I3 and equalizer levers and that due tosuch connection the brake heads of each pair of heads are free to 4moverelative to each other and to the respective brake beam.

This provides for the equalizationl of pressures 'on the brake sh'oes ofeach pireven though one brake shoe of the pair be of Jgreatenthicknessvthan the other.

The tread of 'each wheel 2 is adapted to' be frictionally engaged atdiametrically opposite sides of the wheel by a brake shoe I5 carried bya brake head I3 which isfsllpported from the truck frame by meansl of ahanger Il.,A I

'Each brakehead I5 is operatively-connected to theouter end of ahorizontally disposed lever I3 which extends substantially parallelwiththe adjacent brake beams 9 and I0, ,as the case may be, and which isoperatively connected at its inner end tov a jaw forming the outer endof a member I 3which may be integraLwith. the brake 'beam. y Locatedbetween the brake beams 9. and I0 and extending parallel -with saidbeams are equalizer levfers2l and 2 I. AEach 'end of the equalizer levertogether intermediate 2li-is operatively connected to the adjacent leverI8 through the medium of vertically spaced par'- allel pull rods or bars22, the inner endsof the links being pivotally connected to the lever 20 by means of a pin 23 and the outer'ends being pivotally connected tothe lever I3 bylmeans of a pin 24. Each 'end of the equalizerlever 2I is.connected in like manner to the adjacent lever I8, the links 22 beingdisposed one above and one below the brake beam I and the levers I3 and2|.

' Located between the brakedrum and above the axle I and extendingtransverselyof the axle is a brake cylinder 25 which is bolted orotherwise secured'to aportion 26 of the truck frame. This brake cylindermay be f the usual type comprising a cylinder casing in which there ismounted a piston having-a hollow st em`21 in which there is mounted thepush rod 28. 'Ihe brake cylinder piston is not shown in the drawings but4since the construction of this actuating element is well known ashowingthereof is deemed unnecessary.

.The pressure chamber of the brake cylindersis lever being operativelyconnected to the equalizer lever through the medium of a clevis 32.

The outer end of the brake cylinder push rod 28 is operatively connectedto the upper e'nd of a vertically disposed brake cylinder lever 33,which lever at its lower end is operatively con- `nected to theequalizer lever 2| through the medium of a clevis 34; f

'Ihe levers 3| and`33 are operatively connected their ends by a pull rod'or connecting rod 35.

It will here be noted that the pivotal connection between each lever I8and the adjacent `brake beam is located nearer to the member I9 ofthebrake beamsv than to the pivotal connection between the lever and theassociated brake head I6. This is done in-order to so divide the powertransmitted by one end vof the equalizing levers 20.01?

2 as the case may be that one-third will be tran"s,n e

mitted to the brake 'shoe I5 engaging the tread of the wheel and theremainder will be applied vto the brake beam and through the equalizing5, the lever lever I I to the associated brake shoes acting to dividethe power transmitted thereto equally between the two brake shoes 5. Itwill be understood that by.changing the length of the arm of the leverlI8, the proportion of power transmitted to the brake shoeswillcorrespondingly change.

i Y'operation of mechanism In order to eilect an application of thebrakes iluid' under pressure' is supplied through the conduit 23 tod thepressure chamber lof the brake thereby the piston stem- 21 and pistonrod 23 to move outwardly, the push rod actuating the cylindercausingfthe brake cylinder pistonand brake cylinder lever 33 and thedead lever 3I to move the equalizlng levers 20 and 2| toward each other.

The levers' 23 and 2|, as they are thus moved.' actuate the levers I3 tomove the brake shoes I5 into braking engagement with the wheels 2 and tomove the brake beams 3 and I0 toward each other, causing the brake shoes5to engage the brake drums 3. With the brake shoes 5 in engagement withthe drums, the equalizer levers Il act-to transmit the same brakingpower to each brake shoe of each pair of shoes. With the brake shoes 5and 'I5 in :engagement with the wheels and drums, respectively, thelevers 20 and '2i function to equalize `the power transmitted to thelevers 8.

It will be apparent that when al1-application of the brakes hasnbee'neffected the brake shoes s besides acting' to retard the ,motionoffthewheel and axle assembly also act to maintain the treads of thewheels free of dirt which mightotherwise collect thereon, thus insuringthe maximum adhesion betweenthe wheels andthe track rails.

When it is desired to release the brakes,'tluid under pressure is ventedbyway of conduit 29 I from the pressure chambervofthe brake cylintheirnormal `release p ositions.

While one illustrative embodimentol' the invention has been described indetail, it is not my intention'to limit its scope to that embodiment orotherwise than byfthe terms of 'the appended claims.

Having' now described ny invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a'brake mechanism for a wheel of a rally -way vehicle, incombination, a brake drum rol i tatable 'with said wheel a brakeelementmovable into braking engagement with said brake drum, a brakeelemen't movable into braking engagement with said wheel, and powertransmitting and dividing means for actuating both of said brakeelements. f I

2. In a brake mechanism for a wheel and axle assembly. of a railwayvehicle, in combination, a brake drum rotatable with saidv assembly, abrake element movable into braking engagement with said brake drum, abrake element movable into braking engagement with a wheel of saidassembly, and power transmitting and dividing means for actuating bothvof said brake elements.

3. In a brake mechanismffor a wheel and axle assemblyof a railwayvehicle, in combination, a brake drum rotatable with said assembly,brake elements disposed in c lasp arrangement about each ,wheel of saidassembly and movable into braking engagement with the wheel, brake ele.ments disposed in clasp arrangement about said drum and movable intobrakingy engagement with the drum, and power transmitting and dividingmeans for actuatingsaid brake elements.

4. In a brake mechanism for a wheel of al railway vehicle, incombination, a brake drum ro- 'tatable with said wheel, a brake elementmovable into. brakingy engagement with said brake drum,

a brake element movable into braking engagement with said wheel, meansfor actuating the iirst mentioned brakeelement, and mechanism foractuating said means and second mentioned with said wheel, a memberoperable to effect the operation of the iirst mentioned brake element,and levermeans operable to actuate said member and second mentionedbrake element.

6. In a brake mechanism for a wheel of a Vrailway vehicle, incombination, a brake drum rotatable with said wheel.. a brake elementmovable into braking engagement with said hrake.

drum, a brake element movable into braking engagement with said wheel, abrake beam operable to eiiect the operation of the iirst mentioned brakeelement, a lever operable to actuate said brake beam and secondmentioned brake ele- `-ment, and means for actuating said lever.

7. In a brake mechanism for a wheel-of -a railway vehicie, incombination, a brake drum ro.

ment -with said wheel, a brake beam operable to eiect the operation ofthe first mentionedbrake element, and a lever connecting said brake beamand second mentioned brake element operative y to actuate the beamandsecond mentioned brake element.V

8. In a brake mechanism for a wheel of a railway vehicle, incombination, a brake drum rotatable with said wheel, a brake element.lmovable into braking engagement with said brake drum,

a brake element movable into braking engagement with said wheel, abrakebeam operable to l eiect the operation of the iirst mentioned brakean equalizing lever for actuating said brake elevments, a member foractuating said equalizing lever, a single brake element movable intobraking engagement with a wheel of said assembly, and

power transmitting' and dividing means for actuating said single brakeelement and member. l0. In a brake mechanism for a wheel of a railwayvehicle, in combination, a brake drum 'rotatable with said wheel, a pairof brake elements movable into braking engagement with said drum, anequalizing lever for actuating said brake elements, a member foractuating said equalizing lever, a single brake element movable -intobraking engagement with a wheel of said assembly, a lever operable toactuate said' membei' and said single brake element, and means foractuating said lever.

1l. In a brake mechanism for a wheel and axle assembly oi' a railwayvehicle, in combinatiom two brake drums rotatable with said assembly, a

pair of/brakeelements operable into braking en g gagement with each ofsaid drums, an equalizerv lever'for actuating each pair oi' brakeelements,

a brake beam operative to actuate both equalizer levers, a brake elementoperative into `braking engagement with each wheel of said assembly,

means i'or actuating .said brake beamv and la'st mentioned brakeelement, and 'equalizing power transmitting means for actuatingsaid'means.

12. In a brake mechanism for a wheel andv axle assembly of a railwayvehicle, in combination, two brake drums rotatable with said assembly, a

plurality of brake elements movable into braking a brake element movableinto braking engagement with each wheel ofsaid assembly, and means foractuating the last mentioned brake element and equalizing powertransmitting mechanism.

13. In a brake mechanism for a wheel and axle I assembly of a railwayvehicle, in combination,

two brake drums rotatable with said assembly, a plurality of brakeelements movable into braking4 engagement withl said drum, an

equalizing power transmitting` mechanism for said brake elements, abrake element movable into braking engagement with each wheel -ot saidassembly, lever means operative toy actuate said equalizing powertransmitting means and each ments at each side of the brake drums, asingle brake element located ateach side of each l'wheel of the assemblymovable into braking engagement with-the respective wheel, ltwo leversfor actuating the equalizing power transmitting means and the lastmentioned brake element on one side of each wheel, and equalizing powertransmitting means for actuating said levers.

15. In a brake mechanism for a wheel and axle assembly of a railwayvehicle, incombination, a

plurality of brake drums lsecured to said assembly vto rotatetherewith,4 two sets of a plurality of brake elements disposed in clasparrangement about each drumv and movable into braking engagement withthe drum, two brake elements disposed in clasp arrangement about eachwheel o! said assembly, two equallzlng power transmitting mechanismarranged one at each side' of the assembly and each operable to actuatethesets of brake elements at the same aldeof the assembly, twoleversarranged at each side of the assembly operative to actuate 'the'.equalizing power transmitting means, and eachv lever being adapted toactuate one of the second mentioned brake elements, and equalizing powertransmit- -ting means for actuating all of the levers. 16. In a brakemechanism for awheel and axle assembly of a railway vehicle. incombination,.a

plurality of brake drums secured to said assembly `to rotate therewith,two sets of 'a plurality of brake elements disposed in clasp arrangementabout each drum and'movable into braking engagement with the drum, twobrake elements disposed in clasp arrangement about each wheel of saidassembly, two equallzing power transmitting mechanism arranged one ateach side of the assembly and each operable toactuate the sets of brakeelements at the same side of the'y assembly, two levers arranged at eachside .of the assembly operative to actuate the equalizing powertransmitting meanaand each lever being adapted to actuateone of thesecond mentioned brake elements, a system of operatively connected brakerigging members for actuating all of said levers, and a brake cylinderfor actuating said brake rigging members.

17. In a brake mechanism for a wheel and axle.

assembly of a railway vehicle, in combination, a plurality of brakedrums secured to said assembly to rotate therewith, two sets of aplurality of brake .elements disposed in clasp arrangement vabout eachdrum and movable-into braking en` gagement with the drum, two brakeelements dis- 30 posed in'clasp arrangement a out each wheel of saidassembly, t'wo equalizlng-power transmitting i assembly operative to Ractuate` the equalizingA powertransmitting means, and each lever beingadapted to actuate one of the second mentioned brake' elements,'a systemof operatively connected brake rigging -members for actuating all ofsaid levers, and a brake cylinder arranged between said drums and vabovethe axle of the wheel and axle assembly for actuating said brake Y.

rigging members. l

CLYDE C.y FARMER.

